1. Field of the Invention
The present invention relates to a weft length measuring storage unit of a shuttleless loom, and in more particular, to a weft length measuring storage unit suitable for a fluid jet loom such as a water jet loom.
2. Description of Related Art
As one of weft length measuring storage units of water jet looms, there is an art of measuring the length and storing a weft by winding the weft around the periphery of an immovable drum by a yarn winding tube which is rotated along the periphery of the drum with the rotation of the main shaft of a loom. In this conventional art, the loom is inched or reversed after it is stopped, with the weft length measuring storage unit disconnected from the main shaft, and then the loom is operated again after synchronizing the weft length measuring storage unit with the main shaft.
As another art, there is a weft length measuring storage unit comprising a length measuring section for measuring the length of a weft nipped between a pair of length measuring rollers to be rotated in synchronization with a main shaft, and a storage section for storing by an air current the weft fed from the length measuring section until weft insertion is started. In this conventional art, generally after a loom is stopped, the length measuring rollers are separated from each other so as not to feed the weft when the loom is to be inched or reversed, and then when operation is to be resumed, the so-called synchronization to bring the length measuring rollers into contact with each other is made with the weft of a predetermined length stored.
There is still another length measuring storage unit comprising a length measuring section for measuring the length of a weft nipped between a pair of length measuring rollers, and a storage section for storing the weft fed from the length measuring section with the weft wound around the periphery of an immovable drum by a yarn guide. In this conventional art, one roller and a yarn guide are connected to a main shaft and rotated by the main shaft. Also, when performing an operation to pass the weft through the weft length measuring storage unit, an engagement pin is separated from the periphery of the immovable drum, and the length measuring rollers are separated from each other by pressing a button.
However, in the first prior art, a mechanism for disconnecting the weft length measuring storage unit and the main shaft as well as a mechanism for driving the weft length measuring storage unit for synchronization of the weft length measuring storage unit with the main shaft, etc., are required, which makes the unit large-sized.
In the latter two prior arts, if the looms are inched or reversed while the operation to separate the length measuring rollers is inadvertently neglected, there will arise such problems as an undesirable length measuring action is made to cause a weft newly pulled out of a weft package to wind around the length measuring rollers or to be pulled back toward the side of a weft inserting nozzle to come off the nozzle. Once such problems arise, it will take much time to get rid of the problems.